Q156742: INFO: STL Sample for the replace_copy Function

Article: Q156742
Product(s): Microsoft C Compiler
Version(s): 4.2,5.0,6.0
Operating System(s): 
Keyword(s): kbcode kbVC420 kbVC500 kbVC600 kbDSupport
Last Modified: 27-MAR-2002

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The information in this article applies to:

- The Standard C++ Library, used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 4.2, 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
   - Microsoft Visual C++.NET (2002) 
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SUMMARY
=======

The sample code below illustrates how to use the replace_copy STL function in
Visual C++.

MORE INFORMATION
================

Required Header
---------------

     <algorithm>

Prototype
---------

     template<class ForwardIterator, class OutputIterator, class Type> inline
     OutputIterator replace_copy(ForwardIterator first,

                                ForwardIterator last,
                                OutputIterator result,
                                const T& old_value,
                                const T& new_value)

NOTE: The class/parameter names in the prototype do not match the version in the
header file. Some have been modified to improve readability.

Description
-----------

The replace_copy algorithm copies all elements from the range [first, last) to a
same-size range starting at result, replacing all occurrences of old_value with
new_value in the resulting sequence. It returns an iterator positioned
immediately after the last new element in the resulting sequence.

Sample Code
-----------

NOTE: The first line in the sample code section says:

  // Compile options needed: /GX

In VC++ .NET, /EHsc is set by default and is equivalent to /GX.

  ////////////////////////////////////////////////////////////////////// 
  // 
  // Compile options needed: /GX
  // 
  // replace_copy.cpp : Illustrates how to use the replace_copy function.
  // 
  // Functions:
  // 
  //    replace_copy - Copy the elements of a sequence to another
  //                   same-size sequence replacing any elements
  //                   that match a value with another value.
  // 
  // Written by Kalindi Sanghrajka
  // of Microsoft Product Support Services,
  // Software Core Developer Support.
  // Copyright (c) 1996 Microsoft Corporation. All rights reserved.
  ////////////////////////////////////////////////////////////////////// 

  // disable warning C4786: symbol greater than 255 character,
  // okay to ignore

  #pragma warning(disable: 4786)

  // disable warning C4244: possible loss of data,
  // okay to ignore

  #pragma warning(disable: 4244)

  #include <iostream>
  #include <vector>
  #include <algorithm>
  #include <functional>

  #if _MSC_VER > 1020   // if VC++ version is > 4.2
     using namespace std;  // std c++ libs implemented in std
     #endif

  void main()

  {

      const int MAX_ELEMENTS = 8 ;

      // Define a template class vector of integers
      typedef vector<int, allocator<int> > IntVector ;

      //Define an iterator for template class vector of integer
      typedef IntVector::iterator IntVectorIt ;

      //vector containing numbers
      IntVector Numbers(MAX_ELEMENTS), Result(MAX_ELEMENTS) ;

      IntVectorIt start, end, it, last, resultIt ;

      //Initialize vector Numbers
      Numbers[0] = 10 ;
      Numbers[1] = 20 ;
      Numbers[2] = 10 ;
      Numbers[3] = 15 ;
      Numbers[4] = 12 ;
      Numbers[5] = 7 ;
      Numbers[6] = 9 ;
      Numbers[7] = 10 ;

      start = Numbers.begin() ;   // location of first
                                  // element of Numbers

      end = Numbers.end() ;       // one past the location
                                  // last element of Numbers

      resultIt = Result.begin() ; // location of first
                                  // element of Result

      // print content of Numbers
      cout << "Numbers { " ;
      for(it = start; it != end; it++)
          cout << *it << " " ;
      cout << " }\n" << endl ;

      // copy all elements from Numbers to Result
      // replacing any item that equals 10 with 30
      last = replace_copy(start, end, resultIt, 10, 30) ;

      //print number of elements copied to Result
      cout << "Total number of elements copied to Result = "
          << last - resultIt << endl ;

      start = Result.begin() ;   // location of first
                                  // element of Result

      end = Result.end() ;       // one past the location
                                 // last element of Result

      // print content of Result
      cout << "Result  { " ;
      for(it = start; it != end; it++)
          cout << *it << " " ;
      cout << " }\n" << endl ;

  }

Program Output is:

Numbers { 10 20 10 15 12 7 9 10  }
<BR/><BR/>
Total number of elements copied to Result = 8
Result  { 30 20 30 15 12 7 9 30  }

REFERENCES
==========

Visual C++ Books On Line: Visual C++ Books:C/C++:Standard C++ Library Reference.

Additional query words: STL STLSample replace_copy

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Keywords          : kbcode kbVC420 kbVC500 kbVC600 kbDSupport 
Technology        : kbVCsearch kbAudDeveloper kbVCLibrary
Version           : :4.2,5.0,6.0
Issue type        : kbinfo

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